The Obama administration on Friday announced the broadest liberalization of travel to Cuba in a decade, making it easier for American students and religious and cultural groups to visit the Communist-ruled island.

It still will not be legal for ordinary American tourists to vacation in Cuba, which has been under a U.S. economic embargo for nearly 50 years.

But the measures will expand the categories of who is authorized to travel, which are currently restricted to Cuban Americans and a limited number of others. They also will allow U.S. citizens to send up to $2,000 a year to help Cubans support religious institutions or run small businesses.

"We see these changes as increasing people-to-people contact, helping strengthen Cuban civil society and, frankly, making Cuban people less dependent on the Cuban state," said a senior administration official, who briefed reporters on the condition his name was not used.

The changes come as Cuba is approaching a potential watershed, a Communist Party Congress in April that is expected to intensify changes in the state-run economic model. Supporters of the new regulations say they will allow Americans to help Cuba's nascent private sector. Conservatives and Cuban American legislators are expected to oppose them.

The new head of the House Foreign Affairs Committee, Rep. Ileana Ros-Lehtinen (R-Fla.), said loosening restrictions "will not help foster a pro-democracy environment in Cuba. These changes will not aid in ushering in respect for human rights. And they certainly will not help the Cuban people free themselves from the tyranny that engulfs them."

The rules are similar to ones put in place during the Clinton administration, but rolled back under President George W. Bush.

The new regulations had been drawn up by Obama administration officials last summer. But, wary of political fallout, they had held off introducing them until after the November elections.

Another complicating factor has been the detention of Alan P. Gross, a Potomac contractor who was arrested in Havana in 2009 while working on a secretive U.S. government pro-democracy project. He has not been charged.

Sen. John F. Kerry (D-Mass.), head of the Senate Foreign Relations Committee, has been quietly pressing for the rules to be issued. In a recent letter to Secretary of State Hillary Rodham Clinton obtained by The Post, Kerry wrote "the United States has a choice and an opportunity to be relevant" at a moment when Cuba has allowed more economic freedom.

The new regulations allow authorized religious institutions and universities to issue permits for their members to travel to Cuba. Other cultural and educational groups will be able to seek licenses for such trips. The measures will also allow more U.S. airports to run charter flights to Cuba.

Americans will be permitted to send up to $500 per quarter to Cubans, as long as they are not senior Communist officials.

The regulations do not need congressional approval.

President Obama earlier eased restrictions on Cuban Americans' visits and remittances to the island.